The present invention relates in general to medical infusion devices and in particular to a new and useful device for regulating the flow in a gravity infusion or transfusion device which has a continuously adjustable valve positioned between an inflow channel and an outflow channel.
Such devices, which are currently used in hospitals, clinics and doctor's offices to regulate the flow of fluid to be administered, are frequently designed as roller clamps. Because of the creep characteristics of the tube used to carry the fluid, and the roller clamp, precise dose control cannot be achieved by one setting. As a rule, an exponential decline in drip speed is observable over the course of time. It is particularly difficult to maintain a low drip rate within permissible tolerances for hours at a time.
Furthermore, drip speed is heavily influenced by the patient's venous pressure. When the patient sits up, for example, and his venous pressure thereupon rises, drip speed can decline by 50%.